Disintegratable plug wraps and their applications

ABSTRACT

A filter rod used in manufacture of a smoking article contains: (a) a rod of filter material, and (b) a plug wrap surrounding the rod of filter material. The overlapping side edges of the plug wrap are secured together with a plug wrap adhesive and the plug wrap adhesive comprises a disintegration accelerating agent. Alternatively or in addition, the plug wrap may contain perforations.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/209,186, filed Mar. 13, 2014, which is acontinuation application of U.S. patent application Ser. No. 13/532,504,filed on Jun. 25, 2012 (U.S. Pat. No. 8,707,966, issued Apr. 29, 2014),entitled DISINTEGRATABLE PLUG WRAPS AND THEIR APPLICATIONS, which is acontinuation of U.S. patent application Ser. No. 13/291,828, filed Nov.8, 2011 (now abandoned), which is a continuation application of U.S.patent application Ser. No. 13/071,819, filed on Mar. 25, 2011 (nowabandoned), which claims priority under 35 U.S.C. §119(e) to U.S.Provisional Patent Application No. 61/318,267, filed on Mar. 26, 2010(now expired), the entire content of each is incorporated herein byreference.

BACKGROUND

Smoking articles, such as cigarettes, generally have a substantiallycylindrical rod shaped structure which typically includes a roll orcolumn of smokable material, such as shredded tobacco, surrounded by apaper wrapper. Many types of cigarettes may have a cylindrical filtersegment aligned in an end-to-end relationship with the tobacco rod(“filtered smoking articles”). The filter segment may comprise one ormore plugs formed from a tow of filtering materials, such as celluloseacetate, circumscribed by a paper material known as “plug wrap” therebyforming a “filter plug.” The opposite ends of the plug wrap can besecured together with a plug wrap adhesive. Typically, the filtersegment can be attached to one end of the tobacco rod using acircumscribing wrapping material known as “tipping paper.” The tippingpaper and plug wrap may be bonded to each other through an “anchoringadhesive”.

After a filtered smoking article is consumed, it is discarded. Adhesionof the filter plug wrap to the filter rod in the smoking article, inparticular, when a non-water soluble adhesive is used, may delay theexposure of the filtering material to the environment and slow thefilter disintegration, thereby contributing litter to the environment.To reduce the environmental burden of discarded filtered smokingarticles, there is interest in developing cigarette filter plugs havingan improved degradation rate.

SUMMARY

The present disclosure provides a filter rod used in manufacture of asmoking article, comprising (a) a rod of filter material, and (b) a plugwrap surrounding the rod of filter material with overlapping side edgesof the plug wrap being secured together with a plug wrap adhesive,wherein the plug wrap adhesive comprises a disintegration acceleratingagent and/or the plug wrap may contain perforations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary plug wrap havingperforations.

FIG. 2 shows a photograph of a partial plug wrap having one row ofperforations with 60 holes/inch taken by a Zeiss Stereo Lightmicroscope.

FIG. 3 shows a photograph of a partial plug wrap having one row ofperforations with 90 holes/inch taken by a Zeiss Stereo Lightmicroscope.

DETAILED DESCRIPTION

As used herein, the term “disintegration accelerating agent” denotes anagent capable of improving disintegration rate (or acceleratingdisintegration) of a material, e.g., a paper, at predeterminedconditions. For example, a disintegration accelerating agent can beincorporated in a plug wrap adhesive, which acts as a carrier for thedisintegration accelerating agent, and upon activation, thedisintegration accelerating agent can accelerate disintegration of theplug wrap, thereby helping exposure of the filtering materials to theenvironment for further disintegration.

As used herein, the term “smoking article” denotes an article containinga charge of smoking composition formed into a rod or column, and whichmay optionally be surrounded by a wrapper, which helps to hold the shapeof the rod and contain the smoking composition within the smokingarticle. The rod of smoking material, or the wrapper therefor, or bothcan be burned or heated during use of the smoking article under smokingconditions. A smoking article may also contain one or more filter plugs,which can function to remove targeted constituents from, and provideaesthetically pleasing qualities to, the smoke. The term “smokingarticle” is intended to include cigarettes, cigars, etc. Cigarettesinclude both traditional cigarettes and non-traditional cigarettes.

As used herein, the term “traditional cigarette” denotes a cigarettethat can be smoked by lighting an end of a wrapped rod or column of asmoking composition and drawing air predominantly through the lit end bysuction at a mouthpiece end of the cigarette.

In addition, non-traditional cigarettes include, but are not limited to,cigarettes for electrical smoking systems as described incommonly-assigned U.S. Pat. Nos. 6,026,820; 5,988,176; 5,915,387;5,692,526; 5,692,525; 5,666,976; and 5,499,636. Other non-traditionalcigarettes include those having a fuel element in the tobacco rod asdescribed in U.S. Pat. No. 4,966,171. Other non-traditional cigarettesinclude those having a fuel element in the tobacco rod as described inU.S. Pat. No. 4,966,171.

As used herein, the term “porous” denotes a condition which allows aliquid, a vapor or a gas to pass through it. In contrast, the term“non-porous” denotes a condition which does not allow a liquid, a vaporor a gas to pass through it.

In accordance with one embodiment, a filter plug for smoking article,comprises a filter rod and a plug wrap surrounding the filter rod, theoverlapping side edges of the plug wrap being secured together with aplug wrap adhesive containing a disintegration accelerating agent.

Adhesives for the plug wrap adhesive described herein are notparticularly limited and can comprise hot melt adhesives or other plugwrap adhesives. For example, the plug wrap adhesive may comprise a waterinsoluble hot melt adhesive. Examples of suitable water insoluble hotmelt adhesives may include, but are not limited to, polyvinyl acetateand the like. Water soluble adhesives can also be used for the plug wrapadhesive described herein. Examples of suitable water soluble adhesivesmay include, but are not limited to, polyvinyl alcohol, and the like.When a water soluble adhesive is used as the plug wrap adhesive, it maybecome diluted or dissolved by moisture in the environment, and thusweaken its bonding capability. As a result, opening of the plug wrap canbe accelerated. However, when a water-soluble adhesive is employed, itmay be necessary to reduce the amount of water therein duringmanufacturing in order to effect bonding, which may lengthen andcomplicate the manufacturing process. In a preferred embodiment, theplug wrap adhesive is a water insoluble hot melt adhesive.

As described herein, the plug wrap adhesive can act as a carrier for thedisintegration accelerating agent and release the same in an activatedform when it comes into contact with sufficient moisture. For instance,water molecules can rehydrate and activate the disintegrationaccelerating agent, such as an enzyme, allowing the enzyme to digest theplug wrap. The weakened plug wrap paper ruptures more readily than anundigested paper. Moreover, the presence of moisture can facilitatemovement of the disintegration accelerating agent from the adhesive intocontact with the plug wrap.

The disintegration accelerating agent described herein preferablycontains an enzyme, such as a cellulase and the like. The cellulase maybe from a variety of organisms. Examples of suitable enzymes mayinclude, but are not limited to, cellulases from Trichoderma viride,Aspergillus niger, Sporotrichum thermophile, Chaetomium cochliodes, etc.

The amount of the disintegration accelerating agent incorporated dependson various factors, such as the nature (e.g., activity) of thedisintegration accelerating agent and the degree of disintegrationdesired in a specific time period. In one embodiment, an enzyme can beused in an amount of up to about 100 milligrams, and ranges therebetweenincluding from about 1 mg to about 10 mg, from about 10 mg to about 20mg, from about 20 mg to about 30 mg, from about 30 mg to about 40 mg,from about 40 mg to about 50 mg, from about 50 mg to about 60 mg, fromabout 60 mg to about 70 mg, from about 70 mg to about 80 mg, and fromabout 80 mg to about 90 mg, per gram of plug wrap paper. As used herein,the term “about” is intended to mean plus or minus 10% of thequantitative value described.

Optionally, the plug wrap adhesive described herein may containstabilizers and/or antioxidants which do not interfere with thedisintegration accelerating agent. Examples of suitable stabilizersand/or antioxidants may include, but are not limited to, high molecularweight hindered phenols and multifunctional phenols. Examples ofsuitable hindered phenols may include, but are not limited to,1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxy-benzyl)benzene,pentaerythritoltetrakis-3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate,n-octadecyl-3,5-di-tert-butyl-4-hydroxyphenol)-propionate,4,4′-methylenebis (2,6-tert-butylphenol), 4,4′-thiobis(6-tert-butyl-o-cresol), 2,6-di-tert-butylphenol,6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-1,3,5-triazine,di-n-octadecyl-3,5-di-tert-butyl-4-hydroxy-benzyl-phosphonate,2-(n-octylthio)ethyl-3,5-di-tert-butyl-4-hydroxybenzoate, and sorbitolhexa[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate]. Examples ofsuitable multifunctional phenols may include, but are not limited to,phenols containing sulfur and/or phosphorous atoms.

Furthermore, other additives may also be incorporated into the hot meltadhesive described herein in order to modify certain properties thereof.For example, colorants, such as titanium dioxide, and fillers, such astalc and clay, etc., may be incorporated in small amounts, e.g., lessthan about 20% by weight. Other thermoplastic and/or hydrophilicpolymers may also be added to impart flexibility, toughness, strengthand/or water sensitivity. Examples of suitable thermoplastic polymersmay include, but are not limited to, ethylene vinyl acetate, ethyleneacrylic acid, ethylene methyl acrylate and ethylene n-butyl acrylatecopolymers and the like. Examples of suitable hydrophilic polymers mayinclude, but are not limited to, polyvinyl alcohol, hydroxyethylcellulose, hydroxypropyl cellulose, polyvinyl methyl ether,poly(ethylene oxide), polyvinyl pyrrolidone and the like.

The plug wrap adhesive described herein may be formulated usingtechniques known in the art. In an exemplary procedure, a disintegrationaccelerating agent is admixed with an adhesive and any other additivesin a mixing vessel, preferably a heavy duty mixer which is equipped withrotors, to thereby obtain a smooth and homogeneous mass. Heat may beapplied during mixing, if required or desired.

The filter rod can be made from a material which can serve as anadditive carrier. The filter material may be porous or non-porous.Examples of suitable porous materials include, but are not limited to, anonwoven material, a porous foam, poly(β-hydroxy butyrate co β-hydroxyvalerate) (PHBV), cellulose acetate (CA) fibers and mixtures thereof.Examples of suitable non-porous materials include, but are not limitedto, a water-swellable polymer, a hydrophilic polymer and mixturesthereof. Examples of suitable water-swellable polymers include, but arenot limited to, hydroxypropyl methylcellulose, low substitutedhydroxypropyl cellulose, hydroxypropyl cellulose and mixtures thereof.Further, examples of suitable hydrophilic polymers include, but are notlimited to, esters of polyvinyl alcohols, polysaccharides, alginates,pectins, gelatins, modified cellulosics, starches, super-absorbentpolymers and mixtures thereof.

Preferably, the filter rod comprises a porous material. More preferably,the filter rod comprises cellulose acetate fibers.

The plug wrap which can be used in the filter plug as described hereinis not particularly limited as long as it can provide the desiredintegrity of the filter plug. Preferably, the plug wrap is made of amoisture disintegrative sheet material, such as a paper with no wetstrength chemicals. In one embodiment, the filter plug contains acellulose-based paper.

The filter plug described herein can be manufactured by any suitablemethod. In one embodiment, the plug wrap adhesive can be applied to oneside edge of a plug wrap paper strip and the adhesive treated plug wrappaper is wrapped circumferentially around a compressed rod of filteringmaterial to overwrap, and thereby adhere to, the other side edge of theplug wrap paper. When heat is required, it can be applied by anyconvenient method, e.g., using a heated nozzle, or by direct applicationvia a narrow wheel or roller. The applied temperature will depend, atleast partially, on the adhesive material used.

According to another embodiment, a filter plug for smoking article,comprises a filter rod and a plug wrap surrounding the filter rod, theoverlapping side edges of the plug wrap being secured together with aplug wrap adhesive, wherein the plug wrap contains perforations.Additionally, the plug wrap adhesive may contain a disintegrationaccelerating agent.

Perforations on the plug wrap can further facilitate the disintegrationof the plug wrap upon disposal in the environment. Such perforations canbe in any pattern, such as circular, triangular, linear, etc. In anembodiment, the perforations contain continuous cuts or lines, which maytypically be vertical or longitudinal.

FIG. 1 illustrates an exemplary plug wrap having perforations. In thisexample, the plug wrap contains one transverse dotted line perpendicularto the length direction of the plug wrap and three axial dotted linesalong the length direction of the plug wrap.

The density and size of the perforations in the plug wrap can bemanipulated to retain adequate mechanical strength for the integrity ofthe filter plug and also serve as weak lines for the plug to open upquickly, thereby causing the exposure of internal filtering material tothe environment. In an embodiment, the plug wrap contains one or morerows of perforations with about 30 to about 120 holes per linear inch.When there are one or more rows of perforations with less than about 30holes per linear inch in the plug wrap, the accelerated disintegrationeffects are minimal. On the other hand, when the plug wrap contains oneor more rows of perforations with more than about 120 holes per linearinch, the plug wrap may not have sufficient strength and fall aparteasily, which may complicate the manufacturing process. Preferably, theplug wrap contains one or more rows of perforations with about 60 toabout 90 holes per linear inch. Each hole may have the same or differentshapes and/or sizes.

Preferably, all the holes have substantially the same shape and size tosimplify the manufacturing process. In one embodiment, the perforationscontain substantially equally spaced ellipses. The ellipses preferablyhave an average major axis, along the direction of the perforations,ranging from about 0.13 mm to about 0.23 mm, and preferably, from about0.16 mm to about 0.20 mm, and an average minor axis, perpendicular tothe direction of the perforations, ranging from about 0.10 mm to about0.20 mm, and preferably, from about 0.13 mm to about 0.17 mm.

FIG. 2 shows a photograph of a partial plug wrap having one row ofperforations with 60 holes/inch where the substantially equally spacedellipses have an average major axis of 0.19 mm±0.02 mm and an averageminor axis of 0.16 mm±0.02 mm. FIG. 3 shows a photograph of a partialplug wrap having one row of perforations with 90 holes/inch where thesubstantially equally spaced ellipses have an average major axis of 0.18mm±0.02 mm and an average minor axis of 0.14 mm±0.02 mm.

The perforations in the plug wrap may be created prior to, during orsubsequent to the formation of the filter plug, mechanically or bythermal energy transfer (e.g. focused laser beams), printing, embossing,slitting, or other comparable functions. See, e.g., U.S. Pat. Nos.4,404,454; 5,341,824; 5,944,278 and 7,393,313.

The plug wrap disclosed herein can be incorporated in a smoking articlecomprising a tobacco rod and a filter segment attached to one end of thetobacco rod, wherein the filter segment comprises a segment of thefilter rod described herein. In one embodiment, the smoking article is acigarette.

The tobaccos used in these traditional or non-traditional cigarettes arenot particularly limited. Examples of suitable types of tobaccomaterials include, but are not limited to, cured or uncured tobacco suchas flue-cured tobacco, Burley tobacco, Maryland tobacco, Orientaltobacco, rare tobacco, specialty tobacco, reconstituted tobacco,agglomerated tobacco fines, blends thereof, and the like. Thesematerials may be used individually or in combination thereof.Alternatively or additionally, a non-tobacco smoking material may beused.

Further, the tobacco material may be provided in any suitable form.Examples of suitable forms include shreds and/or particles of tobaccolamina, processed tobacco materials, such as volume expanded or puffedtobacco, or ground tobacco, processed tobacco stems, such as cut-rolledor cut-puffed stems, reconstituted tobacco materials, blends thereof,and the like. Genetically modified tobacco may also be used.

The smoking article described herein may further contain a tipping papercircumscribing the filter segment and the tobacco rod. Preferably, thetipping paper and the plug wrap are bonded with an anchoring adhesivecomprising the disintegration accelerating agent as described herein,which can facilitate detachment of the tipping paper from the plug wrapin a waste smoking article, thereby further accelerating disintegrationthereof. The disintegration accelerating agent for the anchoringadhesive may be the same or different from that for the plug wrap.

The filter plug described herein can enhance disintegration of the plugwrap and thus accelerate disintegration of the filter plug. Therefore,upon disposal, disintegration of a smoking article containing suchfilter plug can be accelerated, thereby reducing litter to theenvironment.

While the invention has been described with reference to specificembodiments, variations and modifications may be made without departingfrom the spirit and the scope of the invention. Such variations andmodifications are to be considered within the purview and scope of theinvention as defined by the appended claims.

All of the above-mentioned references are herein incorporated byreference in their entirety to the same extent as if each individualreference was specifically and individually indicated to be incorporatedherein by reference in its entirety.

We claim:
 1. A filter rod used in manufacture of a smoking article,comprising: (a) a rod of filter material, and (b) a plug wrapsurrounding the rod of filter material with overlapping side edges ofthe plug wrap being secured together with a plug wrap adhesive, whereinthe plug wrap comprises two or more rows of perforations.
 2. The filterrod of claim 1, wherein the plug wrap comprises two or more rows ofperforations with about 30 to about 120 holes per inch.
 3. The filterrod of claim 1, wherein the plug wrap comprises two or more rows ofperforations with about 60 to about 90 holes per inch.
 4. The filter rodof claim 1, wherein the plug wrap adhesive comprises a disintegrationaccelerating agent.
 5. The filter rod of claim 4, wherein thedisintegration accelerating agent comprises an enzyme.
 6. A smokingarticle comprising: (a) a tobacco rod, and (b) a filter segment attachedto one end of the tobacco rod, wherein the filter segment comprises asegment of the filter rod of claim
 1. 7. The smoking article of claim 6,wherein the smoking article is a cigarette.
 8. The smoking article ofclaim 6, further comprising: (c) a tipping paper circumscribing thefilter segment and the tobacco rod.
 9. The smoking article of claim 8,wherein the tipping paper and the plug wrap are bonded with an anchoringadhesive comprising a disintegration accelerating agent.
 10. The smokingarticle of claim 9, wherein the disintegration accelerating agentcomprises an enzyme.
 11. The smoking article of claim 9, wherein thedisintegration accelerating agent, upon activation, increases adisintegration rate of the plug wrap.
 12. The smoking article of claim10, wherein the enzyme, upon activation, increases a disintegration rateof the plug wrap.
 13. The smoking article of claim 9, wherein the holesare equally spaced, have the same shape and/or have the same size. 14.The smoking article of claim 9, wherein the filter material comprisescellulose acetate.
 15. The smoking article of claim 9, wherein the plugwrap adhesive comprises a water soluble adhesive.
 16. The smokingarticle of claim 9, wherein the holes are ellipses with sizes of about0.13 to about 0.23 mm along a major axis and about 0.10 to about 0.20 mmalong a minor axis.
 17. The smoking article of claim 9, wherein theholes are ellipses with sizes of about 0.16 to about 0.20 mm along amajor axis and about 0.13 to about 0.17 mm along a minor axis.
 18. Thesmoking article of claim 9, wherein the holes are ellipses with sizes ofabout 0.19 mm along a major axis and about 0.16 mm along a minor axis.19. The smoking article of claim 9, wherein the holes are ellipses withsizes of about 0.18 mm along a major axis and about 0.14 mm along aminor axis.
 20. The smoking article of claim 10, wherein the enzyme isincorporated in an amount of about 1 to about 100 mg per gram of plugwrap paper.